Reciprocating saw

ABSTRACT

A reciprocating saw, including a housing, a spindle mounted for reciprocation relative to the housing, the spindle having an end adapted to receive a saw blade, the saw blade having a first orientation relative to the spindle to have a first cutting direction and a second orientation relative to the spindle to have a second cutting direction opposite the first cutting direction, and a drive assembly connected to the spindle and operable to selectively drive the saw blade along a first path of travel during a first cutting stroke and along a second path of travel during a second cutting stroke. The first path of travel is characterized by movement at least partially in the first cutting direction and the second path of travel is characterized by movement at least partially in the second cutting direction.

RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.09/606,955, filed Jun. 29, 2000, which is a continuation of U.S. patentapplication Ser. No. 09/474,033, filed Dec. 28, 1999, which is acontinuation of U.S. patent application Ser. No. 09/020,436, filed Feb.9, 1998.

FIELD OF THE INVENTION

The present invention generally relates to the field of reciprocatingsaws.

BACKGROUND OF THE INVENTION

Reciprocating saws are used to cut a variety of objects, such as metalpipes, wood and drywall. Such saws typically include a housing and aspindle mounted in the housing for reciprocating motion along an axisthat is parallel to the longitudinal extent of the spindle. An electricmotor provides power to the spindle through a mechanical reciprocatingdevice that converts the rotary motion of a motor shaft to reciprocatingmotion. Such mechanical reciprocating devices can, for example, includean eccentric drive, as disclosed in U.S. Pat. No. 5,079,844, or a wobbleplate drive, as disclosed in U.S. Pat. Nos. 5,025,562 and 5,050,307.

In some reciprocating saws, the spindle reciprocates in an orbitalmotion as opposed to a straight line reciprocating motion. The orbitalmotion is characterized by a forward (i.e., in the cutting direction)motion of the saw blade as the saw blade is being retracted toward thesaw on the cutting stroke, and a corresponding rearward (i.e., oppositethe cutting direction) motion of the saw blade as the saw blade is beingextended away from the saw on the return stroke. The result is acircuitous, or orbital, path of the saw blade. Such orbital motion isbelieved to improve the speed at which the saw cuts a workpiece bydriving the saw blade into the workpiece during the cutting stroke andwithdrawing the saw blade from the workpiece during the return stroke.

Orbital motion has been achieved in a number of different ways. Forexample, in U.S. Pat. Nos. 4,238,884 and 4,628,605, a forward force (inthe cutting direction) is applied by a blade roller directly to the sawblade during the cutting stroke, and forward motion of the saw blade isaccommodated by a forgiving interconnection between the spindle and thedrive mechanism. In U.S. Pat. No. 5,212,887, the spindle reciprocatesthrough a pivotally-mounted bushing, and the back end of the spindle isconnected to an eccentric member that provides forward-rearward motionto the spindle. In U.S. Pat. Nos. 4,962,588 and 4,550,501, the back endof the spindle is moved forward-rearward by connection to a cam surfaceon a rotating gear, and in U.S. Pat. No. 5,392,519 the back end of thespindle in moved forward-rearward by connection to an eccentric member.

SUMMARY OF THE INVENTION

The utilization of blade rollers, cam surfaces, and eccentric memberscan be unnecessarily complicated and expensive. Further, such devicestend to wear down, and some can introduce unwanted vibrations into thesaw. Accordingly, it is an object of the present invention to provide asaw that approaches the better cutting performance of orbital sawswithout the complexity required for orbital motion. It is a relatedobject of the present invention to achieve a forward motion of the sawblade during the cutting stroke without resorting to orbital motion.

The above-noted objects are achieved by a method of reciprocating aspindle of a reciprocating saw, the spindle generally having a front endadapted to receive a saw blade movable through a cutting stroke and areturn stroke. The method generally comprises the steps of reciprocatingthe front end along a first path (e.g., a neutral path) during thecutting stroke and along the same first path during the return stroke,and adjusting the saw such that the front end reciprocates along asecond path during the cutting stroke and along the same second pathduring the return stroke. The second path is oblique to the first path.By virtue of this method, the front end of the spindle follows a paththat is not orbital, and therefore can be achieved using a much simplermechanism. In addition, the front end of the spindle can be moved in aneutral path or, alternatively, in an oblique path that plunges into theworkpiece.

In another aspect, the present invention provides a method ofreciprocating a spindle of a reciprocating saw, the spindle having afirst cutting direction and a second cutting direction opposite thefirst cutting direction. The method generally comprises the steps ofmoving the front end along a first cutting path during the cuttingstroke, the first cutting path characterized by movement at leastpartially in the first cutting direction, returning the front end alonga return stroke (e.g., along the first cutting path), and adjusting thesaw such that the front end moves along a second cutting path during thecutting stroke, the second cutting path characterized by movement atleast partially in the second cutting direction. Preferably, the saw canalso be adjusted such that the front end moves along a neutral cuttingpath during the cutting stroke, the neutral cutting path characterizedby movement substantially perpendicular to the first and second cuttingdirections. By virtue of this method, the saw can be used to achieve aplunge cut in either down-cutting or up-cutting situations.

In addition, in some aspects, the invention provides a reciprocating sawgenerally comprising, a housing, a spindle mounted for reciprocationrelative to the housing, the spindle having an end adapted to receive asaw blade, the saw blade having a first orientation relative to thespindle to have a first cutting direction and a second orientationrelative to the spindle to have a second cutting direction opposite thefirst cutting direction, and a drive assembly connected to the spindleand operable to selectively drive the saw blade along a first path oftravel during a first cutting stroke and along a second path of travelduring a second cutting stroke. The first path of travel ischaracterized by movement at least partially in the first cuttingdirection and the second path of travel is characterized by movement atleast partially in the second cutting direction.

In another aspect, the present invention provides a method ofreciprocating a spindle of a reciprocating saw, the reciprocating sawincluding a housing, the spindle having an end adapted to support a sawblade for reciprocating movement relative to the housing. The methodgenerally comprises the acts of securing the saw blade to the end of thespindle in a first orientation, in which the saw blade has a firstcutting direction, reciprocating the end of the spindle such that thesaw blade moves along a first path of travel relative to the housing,the first path of travel being characterized by movement at leastpartially in the first cutting direction, adjusting the orientation ofthe saw blade relative to the spindle from the first orientation to asecond orientation, in which the saw blade has a second cuttingdirection opposite the first cutting direction, and reciprocating theend of the spindle such that the saw blade moves along a second path oftravel relative to the housing, the second path of travel beingcharacterized by movement at least partially in the second cuttingdirection.

In addition in some aspects, the present invention provides areciprocating saw generally comprising a housing, a spindle mounted forreciprocation relative to the housing, the spindle having an end adaptedto receive a saw blade, the saw blade having a first orientationrelative to the spindle to have a first cutting direction and a secondorientation relative to the spindle to have a second cutting directionopposite the first cutting direction, and an orbital drive assemblyconnected to the spindle and operable to selectively drive the saw bladealong a first path of travel during a first cutting stroke and along asecond path of travel during a second cutting stroke. The first path oftravel is a first orbital path characterized by movement at leastpartially in the first cutting direction and the second path of travelis a second orbital path characterized by movement at least partially inthe second cutting direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial side section view of a reciprocating saw embodyingthe present invention with the guide member in a down-cutting positionand the spindle in a fully retracted position.

FIG. 2 is the partial side section view of FIG. 1 with the spindle in afully extended position.

FIG. 3 is a front view of the reciprocating saw shown in FIG. 1.

FIG. 4 is a partial right side view of the reciprocating saw shown inFIG. 1.

FIG. 5 is a section view taken along line 5-5 in FIG. 1.

FIG. 6 is a section view taken along line 6-6 in FIG. 1.

FIG. 7 is a right side view of the reciprocating saw taken along line7-7 in FIG. 5.

FIG. 8 is a section view taken along line 8-8 in FIG. 5.

FIG. 9 is a section view taken along line 9-9 in FIG. 5.

FIG. 10 is a perspective assembly view of the housing insert, followermember, eccentric cam member and adjustment knob.

FIG. 11 is a partial side view of the internal drive components of thereciprocating saw of FIG. 1 with the guide member in a neutral ornon-rocking position.

FIG. 12 is a partial side view of the internal drive components of thereciprocating saw of FIG. 1 with the guide member in an up-cuttingposition.

FIG. 13 is a front perspective view of another construction of a driveassembly for a reciprocating saw.

FIG. 14 is another front perspective view of the drive assembly of FIG.13.

FIG. 15 is a rear perspective view of the drive assembly of FIG. 13.

FIG. 16 is another rear perspective view of drive assembly of FIG. 13.

FIG. 17 is a cross-section view taken along line 17-17 of FIG. 15.

FIG. 18 is a side view of the drive assembly of FIG. 13.

FIG. 19 is an enlarged side view of the drive assembly of FIG. 13.

FIG. 20 is a front view of another construction of a drive assembly.

FIG. 21 is another front view of the drive assembly of FIG. 20.

FIG. 22 is a side view of the drive assembly of FIG. 20.

FIG. 23 is another side view of the drive assembly of FIG. 20.

DETAILED DESCRIPTION

Before at least one construction of the invention is explained indetail, it is to be understood that the phraseology and terminology usedherein with reference to element orientation (such as, for example,terms like “upward”, “downward”, “forward”, rearward”, etc.) are onlyused to simplify description of the present invention, and do not aloneindicate or imply that the element referred to must have a particularorientation. In addition, terms such as “first”, “second” and “third”are used herein for purposes of description and are not intended toindicate or imply relative importance or significance.

FIGS. 1 and 2 illustrate a reciprocating saw 20 embodying the presentinvention. The reciprocating saw 20 generally includes a main housing22, a spindle 24 reciprocatably mounted within the housing 22, and acounterweight 26 reciprocatably mounted with the housing 22. The spindle24 includes a front end 28 that supports a saw blade 30, which isdesigned to cut in a cutting direction 32 (i.e., in the direction of thesaw teeth) opposite a second or non-cutting direction 34. The spindle 24reciprocates the saw blade 30 through a cutting stroke (usually towardthe housing 22) and a return stroke (usually away from the housing 22).The counterweight 26 provides a vibration-reducing force that at leastpartially counteracts the forces created by movement of the spindle 24and the saw blade 30.

The reciprocating saw 20 includes a drive assembly 35, which isconnected to the spindle 24 and is operable to reciprocate the front end28 of the spindle 24 and the saw blade 30 along a number of differenttravel paths.

In illustrated construction of FIGS. 1-12, the drive assembly 35 isoperable to drive the front end 28 of the spindle 24 and the saw blade30 along a first path, which is characterized by rocker motion in thefirst cutting direction 32, and along a second path, which ischaracterized by rocker motion in the second cutting direction 34. Inother constructions, such as the illustrated constructions of FIGS.13-19 and FIGS. 20-23, the drive assembly 35 is operable to drive thefront end 28 of the spindle 24 and the saw blade 30 along a first path,which is characterized by orbital motion in the first cutting direction32, and along a second path, which is characterized by orbital motion inthe second cutting direction 34.

In still other constructions, the drive assembly 35 can drive the frontend 28 of the spindle 24 and the saw blade 30 along a first path, whichis characterized by rocker motion in the first cutting direction 32, andalong a second path, which is characterized by orbital motion in thesecond cutting direction 34. Also, in other constructions, the driveassembly 35 can drive the front end 28 of the spindle 24 and the sawblade 30 along a first path, which is characterized by orbital motion inthe first cutting direction 32, and along a second path, which ischaracterized by rocker motion in the second cutting direction 34.

In still other constructions, the drive assembly 35 can drive the frontend 28 of the spindle 24 and the saw blade 30 along three or more paths,each of which can include orbital motion, rocking motion or neutralmotion (i.e., in a substantially linear direction) and can becharacterized by motion in the first cutting direction 32 and/or thesecond cutting direction 34.

A drive means in the form of an electric motor (not shown) is mounted inthe housing 22. The motor includes a drive pinion 36 that engages a gear38 mounted on a jack shaft 40 that is rotatably mounted within thehousing 22. A wobble shaft 42 is positioned over the jack shaft 40 andis designed to drive primary and secondary wobble plates 44, 46 in aconventional manner. The primary wobble plate 44 includes a primarydrive arm 48 that extends through a slot 50 (FIG. 6) in thecounterweight 26 to drivingly engage the reciprocating spindle 24. Thesecondary wobble plate 46 includes a secondary drive arm 52 thatdrivingly engages the counterweight 26.

In addition to being mounted for reciprocating motion, the reciprocatingspindle 24 is also mounted for rocking motion relative to the housing22. Such rocking motion is facilitated by a spherical bearing sleeve 54pivotably mounted within the housing 22. The spherical bearing sleeve 54rocks relative to the housing 22, and the reciprocating spindle 24reciprocates through the bearing sleeve 54. It should be appreciatedthat, instead of a spherical bearing sleeve 54, the bearing sleeve 54could comprise a plane bearing sleeve mounted to the housing 22 forpivoting motion about a horizontal axis.

The reciprocating spindle 24 of the construction illustrated in FIGS.1-12 is designed to move in three distinct motions: a down-cuttingrocking motion, a neutral or non-rocking motion, and an up-cuttingrocking motion. FIGS. 1 and 2 illustrate the down-cutting rockingmotion. Such motion is generated due to the interconnection between thespindle 24 and an inclined track member 56. Such interconnection isprovided by the interconnection between a rear end 58 of the spindle 24and the counterweight 26, and further by the interconnection between thecounterweight 26 and the inclined track member 56. More specifically,the rear end 58 of the spindle 24 is designed to be supported by and toslide within the counterweight 26. Accordingly, any oblique motion(i.e., angled relative to the longitudinal extent of the reciprocatingspindle 24) of the counterweight 26 will result in oblique motion of therear end of the spindle 24 and rocking motion of the spindle 24 aboutthe spherical bearing sleeve 54.

Referring to FIG. 5, in addition to riding on the reciprocating spindle24, the counterweight 26 is slidably interconnected with the trackmember 56. In this regard, two follower members in the form of bearings60 are secured to opposing sides of the counterweight 26 and slidablyengage a slot 62 in the track member 56. Because the track member 56 isinclined relative to the longitudinal extent of the counterweight 26 (asshown in FIG. 1), the sliding interaction between the counterweight 26and the track member 56 will result in oblique movement of thecounterweight 26 as the counterweight 26 is reciprocated within thehousing 22. More specifically, as the counterweight 26 is moved from theposition shown in FIG. 1 to the position shown in FIG. 2, thecounterweight 26 moves downwardly (as viewed in FIGS. 1 and 2) withinthe housing 22, resulting in upward movement of both the front end 28 ofthe spindle 24 and the corresponding saw blade 30. During this upwardmovement of the saw blade 30, the spindle 24 is being extended. As thespindle 24 is being retracted, the counterweight 26 is extended andmoved upward slightly, following the track member 56. Such upwardmovement of the counterweight 26 results in downward movement of the sawblade 30. Accordingly, it can be seen that the saw blade 30 movesdownward slightly (i.e., in the cutting direction 32) during the cuttingstroke, and upward slightly (i.e., in the non-cutting direction 34)during the return stroke. However, the cutting stroke and return strokeoccur along the same path, and therefore the path of the saw blade 30 isnot orbital.

In the illustrated embodiment, the slot 62 in the track member 56 issubstantially linear. Alternatively, the slot could be curved.

Turning to FIG. 6, in order to accommodate oblique movement of thecounterweight 26, the interconnection between the secondary drive arm 52and the counterweight 26 is provided by a spherical slide bearing 64.More specifically, the spherical slide bearing 64 provides for rockingmotion between the secondary drive arm 52 and the counterweight 26, andthe secondary drive arm 52 is also slidable within the spherical slidebearing 64 to accommodate transverse movement of the counterweight 26relative to the secondary drive arm 52. Similarly, the primary drive arm48 is interconnected with the spindle 24 by a spherical slide bearing(not shown).

In order to allow the path of the saw blade 30 to be adjusted, the angleof the track member 56 is adjustable. More specifically, referring toFIGS. 3-5 and 7-9, the track member 56 is pivotally mounted to a housinginsert 66 by a pivot member 68. Adjustment of the angle of the trackmember 56 is accomplished by rotating an adjustment knob 70. Theadjustment knob 70 can be rotated to provide rotation to an eccentriccam member 72 having an eccentric pin 74 that slidably engages anadjustment slot 76 in the track member 56. As the eccentric cam member72 is rotated, the eccentric pin 74 provides transverse movement to thefront end 78 of the track member 56, thereby causing rotation of thetrack member 56 about the pivot member 68.

Referring to FIG. 10, to secure the position of the track member 56, theadjustment knob 70 is provided with two teeth 80 designed to selectivelyengage three pairs of corresponding recesses 82 in the housing insert66. The adjustment knob 70 is biased toward the housing insert 66 by aspring 84 and a corresponding spring stop 86 secured to the eccentriccam member 72. Rotation of the adjustment knob 70 is accomplished bypulling the adjustment knob 70 away from the housing insert 66 until theteeth 80 are disengaged from the recesses 82 in the housing insert 66.Subsequently, the adjustment knob 70 can be rotated until the teeth 80are aligned with a different pair of recesses 82. The adjustment knob 70can then be released whereby the spring 84 will force the adjustmentknob 70 and corresponding teeth 80 toward the housing insert 66 and intothe corresponding recesses 82. The positions of the three pairs ofrecesses 82 in the housing insert 66 correspond with the three desiredmotions of the saw blade 30: down-cutting rocking motion, neutral ornon-rocking motion, and up-cutting rocking motion.

FIG. 11 illustrates the reciprocating saw 20 with the track member 56 inthe neutral or non-rocking position, resulting in movement of the frontend 28 of the reciprocating spindle 24 in a path different thandescribed above with respect to FIG. 1. Such positioning of the trackmember 56 is accomplished by rotating the adjustment knob 70, asdescribed above in more detail. With the track member 56 in thisposition, the counterweight 26 and spindle 24 will not significantlyrock about the spherical bearing sleeve 54, thereby resulting in aneutral or non-rocking motion of the saw blade 30. The neutral motion ofthe saw blade 30 is generally illustrated in FIG. 11 with the fullyextended position of the saw blade 30 shown in solid lines and the fullyretracted position of the saw blade 30 shown in broken lines. With thetrack member 56 in this position, the reciprocating saw 20 can be usedfor either up-cutting (as illustrated) or down-cutting.

FIG. 12 illustrates the reciprocating saw 20 with the track member 56positioned in an up-cutting rocking position, resulting in movement ofthe front end 28 of the reciprocating spindle 24 in a path differentthan described above with respect to FIGS. 1 and 11. As noted above,such positioning of the track member 56 is accomplished by rotating theadjustment knob 70 to the appropriate position. With the track member 56in this position, the saw blade 30 will follow the illustrated path,with the fully extended position of the saw blade 30 shown in solidlines and the fully retracted position of the saw blade 30 shown inbroken lines. With the track member 56 in this position, thereciprocating saw 20 can be used for up-cutting in a cutting directionopposite that shown in FIG. 1.

To summarize, the down-cutting rocking motion of the saw blade 32 isillustrated in FIGS. 1 and 2. During the cutting stroke (moving from theposition shown in FIG. 2 to the position shown in FIG. 1), the spindle24 is retracted, and the counterweight 26 moves upwardly along the trackmember 56. As a result, a point on the saw blade (e.g., the tip of thesaw blade 32) follows a curvilinear path, moving both toward the housing22 (to the right in FIGS. 1 and 2) and downwardly (in the cuttingdirection 32). During the return stroke (moving from the position shownin FIG. 1 to the position shown in FIG. 2), the tip of the saw blade 32returns along this curvilinear path (moves away from the housing 22 (tothe left in FIGS. 1 and 2) and upwardly (in the non-cutting direction34)) as the spindle 24 is extended and as the counterweight 26 movesdownwardly along the track member 56. The tip of the saw blade 32 thusfollows the same curvilinear path in the return stroke and in thecutting stroke.

The neutral, non-rocking motion of the saw blade 32 is illustrated inFIG. 11. During the cutting stroke (from the position shown in solidlines to the position shown in broken lines), the spindle 24 isretracted, and the counterweight 26 moves along the neutrally-positionedtrack member 56. As a result, the tip of the saw blade 32 follows alinear path, moving only toward the housing 22 (to the right in FIG.11). During the return stroke (moving from the position shown in brokenlines to the position shown in solid lines), the tip of the saw blade 32returns along this linear path (moving only away from the housing 22 (tothe left in FIG. 11)) as the spindle 24 is extended and as thecounterweight 26 moves along the neutrally-positioned track member 56.The tip of the saw blade 32 thus follows the same linear path in thereturn stroke and in the cutting stroke.

Finally, the up-cutting rocking motion of the saw blade 32 isillustrated in FIG. 12. During the cutting stroke (moving from theposition shown in solid lines to the position shown in broken lines),the spindle 24 is retracted, and the counterweight 26 moves downwardlyalong the track member 56. As a result, the tip of the saw blade 32follows a curvilinear path (different from the curvilinear pathillustrated in FIGS. 1 and 2), moving both toward the housing 22 (to theright in FIG. 12) and upwardly. During the return stroke (in FIG. 12,moving from the position shown in broken lines to the position shown insolid lines), the tip of the saw blade 32 returns along this curvilinearpath (moves away from the housing 22 (to the left in FIG. 12) anddownwardly) as the spindle 24 is extended and as the counterweight 26moves upwardly along the track member 56. The tip of the saw blade 32thus follows the same curvilinear path in the return stroke and in thecutting stroke.

FIGS. 13-19 illustrate an alternate construction of a drive assembly 135for a reciprocating saw 120 according to the present invention. Thedrive assembly 135 in FIGS. 13-19 is similar in many ways to theillustrated constructions of FIGS. 1-12 described above. Accordingly,with the exception of mutually inconsistent features and elementsbetween the constructions of FIGS. 13-19 and the constructions of FIGS.1-12, reference is hereby made to the description above accompanying theconstructions of FIGS. 1-12 for a more complete description of thefeatures and elements (and the alternatives to the features andelements) of the construction of FIGS. 13-19. Features and elements inthe construction of FIGS. 13-19 corresponding to features and elementsin the constructions of FIGS. 1-12 are numbered in the 100 and 200series.

The drive assembly 135 illustrated in FIGS. 13-19 is an orbital driveassembly, which is operable to drive the spindle 124 in an orbitalmotion (e.g., reciprocating and pivoting motion) along a plurality oftravel paths, including a first path and a second path. Components oforbital drive assembly 135 may be similar to components shown anddescribed in U.S. Pat. No. 6,249,979, issued Jun. 26, 2001, and U.S.patent application Ser. No. 09/892,096, filed Jun. 26, 2001, the entirecontents of which are hereby incorporated by reference.

For cutting operations in which the drive assembly 135 drives the sawblade 30 along the first path, the saw blade 30 can be oriented withrespect to the front end 128 of the spindle 124 so that the teeth 131(shown in FIGS. 1 and 2) of the saw blade 30 are pointing in a generallydownward direction (e.g., for down-cutting operations). The first pathis characterized by a forward (i.e., in the first cutting direction 132)motion of the saw blade 30 as the saw blade 30 is being retracted towardthe housing 22 (shown in FIGS. 1 and 2) during the cutting stroke, and acorresponding rearward (i.e., in the second cutting direction 134)motion of the saw blade 30 as the saw blade 30 is being extended awayfrom the housing 22 during the return stroke. This motion results in acircuitous or orbital path of the saw blade 30.

For cutting operations in which the drive assembly 135 drives the sawblade 30 along the second travel path, the saw blade 30 can bereoriented with respect to the front end 128 of the spindle 124 so thatthe teeth 131 (shown in FIGS. 1 and 2) of the saw blade 30 are pointingin a generally upward direction (e.g., for up-cutting operations). Thesecond path is characterized by forward (i.e., in the first cuttingdirection 132) motion of the saw blade 30 as the saw blade 30 is beingextended away from the housing 22 during the return stroke, and acorresponding rearward (i.e., in the second cutting direction 134)motion of the saw blade 30 as the saw blade 30 is being retracted towardthe housing 22 during the cutting stroke. This motion also results in acircuitous or orbital path of the saw blade 30.

As shown in the FIGS. 13-19, the drive assembly 135 includes a firsteccentric cam member 188 and a second eccentric cam member 190 supportedon the shaft 140. The first and second cam members 188, 190 have outersurfaces which are eccentric with respect to the axis of the shaft 140so that the outer surface of the cam members 188, 190 rotateeccentrically about the axis of the shaft 140 as the shaft 140 rotates.In the illustrated construction, the first and second cam members 188,190 are connected to the shaft 140 so that the eccentric portions of thefirst and second cam members 188, 190 are out of phase and are spacedapart around the axis of the shaft 140 by about 180 degrees. In otherconstructions, the eccentric portions of the first and second cammembers 188, 190 can be in phase. In still other constructions, theeccentric portions of the first and second cam members 188, 190 can beoriented out of phase by between about 1 degree and about 179 degrees.

The drive assembly 135 also includes a tube chassis 194 that issupported in the housing 22 for pivoting movement relative to thehousing 22. The tube chassis 194 is generally cylindrical and has ahollow inner portion for receiving a portion of the spindle 124.

As shown in FIGS. 13-19, the drive assembly 135 includes a first camfollower 198 and a second cam follower 200. The first cam follower 198includes a head portion 202, which is selectively engageable with a rearportion 214 of the tube chassis 194, and a lower portion 204, which isselectively engageable with the outer surface of the first cam follower198. A pin support member 206 is connected to the housing 22 andsupports the first cam follower 198 so that the first cam follower 198is movable relative to the support member 206 along the longitudinalaxis of the first cam follower 198.

The second cam follower 194 is a generally elongated member and definesan elongated slot 210. As shown in FIGS. 13-19, portions of the tubechassis 194 and the shaft 140 extend through the elongated slot 210. Anupper end 212 of the second cam follower 200 is engageable with the rearportion 214 of the tube chassis 194 and a lower end 216 of the secondcam follower 200 is engageable with the outer surface of the secondeccentric cam member 190.

In operation, the operator orients the saw blade 30 in either anup-cutting orientation (i.e., with the teeth 131 facing in a generallyupward direction) or a down-cutting orientation (i.e., with the teeth131 facing in a generally downward direction).

After the operator has oriented the saw blade 30 in a desiredorientation with respect to the front end 128 of the spindle 124, theoperator selects a travel path for the saw blade 30 by engaging the sawblade 30 with a workpiece. During up-cutting operations, the operatorengages the teeth 131 of the saw blade 30 with a workpiece orientedabove the housing 22, causing the tube chassis 194 to pivot about aforward flanged portion 234 so that the rear portion 214 of the tubechassis 194 is moved upwardly with respect to the housing 22. Duringdown-cutting operations, the operator engages the teeth 131 of the sawblade 30 with a workpiece located below the housing 22, causing the tubechassis 194 to pivot about the forward flanged portion 234 so that therear portion 214 of the tube chassis 194 is moved downwardly withrespect to the housing 22.

In other constructions, the drive assembly 135 can include an orbitaladjustment assembly 228, which is operable to change movement of the sawblade 30 between the first path and the second path. As shown in FIGS.13-19, the adjustment assembly 228 can include a slide 230, which isselectively engageable with the first and second cam followers 198, 200and is operable to move the first cam follower 198 out of engagementwith the first eccentric cam member 188 during up-cutting operations andis operable to move the second cam follower 200 out of engagement withthe second eccentric cam member 190 during down-cutting operations. Theadjustment assembly 228 can also include an actuator. In theseconstructions, a first end of the actuator is engageable with the slide230 and a second end of the actuator extends outwardly through thehousing 22 for activation by an operator.

When an operator selects the first path, the chassis 194 is pivotedabout the forward flanged portion 234 so that the rear portion 214 ofthe chassis 194 engages the head portion 202 of the first cam follower198. The operator can then activate the motor which rotates the shaft140 and the first eccentric cam member 188 about the axis of the shaft140.

As the shaft 140 and the first eccentric cam member 188 rotate about theaxis of the shaft 140, the outer surface of the first eccentric cammember 188 engages the lower portion 204 of the first cam follower 198,causing the first cam follower 198 to reciprocate along its axis. As thefirst cam follower 198 reciprocates, the head portion 202 of the firstcam follower 198 engages the rear portion 214 of the tube chassis 194,forcing the rearward portion 214 of the tube chassis 194 upwardlyrelative to the housing 22.

In this manner, the drive assembly 135 pivots the tube chassis 194relative to the housing 22 about a forward flanged portion 234 of thetube chassis 194, causing the spindle 124 to pivot with the tube chassis194. This pivoting movement of the tube chassis 194 and the spindle 124,in combination with the reciprocating movement of the spindle 124described above, causes the spindle 124 and the saw blade 30 to movealong the first orbital path.

When the operator selects the second path, the chassis 194 is pivotedabout the forward flanged portion 234 so that the rear portion 214 ofthe chassis 194 engages the upper end 212 of the second cam follower200. The operator can then activate the motor, which, rotates the shaft140 and the second eccentric cam member 200 about the axis of the shaft140.

As the shaft 140 and the second eccentric cam member 190 rotate aboutthe axis of the shaft 140, the second eccentric cam member 190 engagesthe lower end 216 of the second cam follower 200, causing the second camfollower 200 to reciprocate along its axis. As the second cam follower200 moves downwardly along its axis, the upper end 212 of the second camfollower 200 engages the tube chassis 194, forcing the tube chassis 194downwardly relative to the housing 22.

In this manner, the drive assembly 135 pivots the tube chassis 194relative to the housing 22 about the forward flanged portion 234 of thetube chassis 194, causing the spindle 124 to pivot with the tube chassis194. This pivoting movement of the tube chassis 194 and the spindle 124,in combination with the reciprocating movement of the spindle 124described above, causes the spindle 124 and the saw blade 30 to movealong the second orbital path.

In some constructions, the drive assembly 135 is also operable to drivethe forward end 128 of the spindle 124 and the saw blade 30 alongadditional paths of travel. Such paths of travel can include orbitaland/or rocker motion and can include motion in the first and/or secondcutting directions 132, 134 as described above.

In addition, in some constructions, such as the illustrated constructionof FIGS. 13-19, the drive assembly 135 is operable to drive the forwardend 128 of the spindle 124 and the saw blade 30 along a neutral path, inwhich the spindle 124 reciprocates along a substantially linear pathdefined by the spindle axis. In these constructions, the drive assembly135 can include a locking assembly 240, which is operable to preventorbital and/or rocking motion of the spindle 124.

As shown in FIGS. 15-16, the locking assembly 240 includes a lockingplate 242, which is pivotably connected to the pin support member 206for movement relative to the housing 22 between a locking position(shown in FIG. 15) and an unlocking position (shown in FIG. 16). In theillustrated construction, the locking plate 242 defines an elongatedopening 244 having stops 246 located at opposite ends of the opening244. The locking assembly 240 can also include an actuator for movingthe locking plate 242 between the locking position and the unlockingposition.

When the locking plate 242 is in the locking position, the stops 246engage upper and lower portions of the tube chassis 194, preventing thetube chassis 194 from moving relative to the locking plate 242 and thehousing 22 and thereby preventing orbital motion and/or rocking motionof the spindle 124. When the locking plate 242 is in the unlockingposition, the stops 246 are moved out of engagement with the tubechassis 194 so that the tube chassis 194 can move upwardly anddownwardly with respect to the housing 22, thereby allowing orbitalmotion and/or rocking motion of the spindle 124.

FIGS. 20-23 illustrate an alternate construction of a drive assembly 335for a reciprocating saw according to the present invention. The driveassembly 335 in FIGS. 20-23 is similar in many ways to the illustratedconstructions of FIGS. 1-19 described above. Accordingly, with theexception of mutually inconsistent features and elements between theconstructions of FIGS. 20-23 and the constructions of FIGS. 1-19,reference is hereby made to the description above accompanying theconstructions of FIGS. 1-19 for a more complete description of thefeatures and elements (and the alternatives to the features andelements) of the construction of FIGS. 1-19. Features and elements inthe construction of FIGS. 20-23 corresponding to features and elementsin the constructions of FIGS. 1-19 are numbered in the 300 and 400series.

As shown in the FIGS. 20-23, the drive assembly 335 includes a firsteccentric cam member 388 and a second eccentric cam member 390 supportedon the shaft 340. The drive assembly 335 also includes a cam follower398 and a pin support member 406, which is connected to the housing 22and supports the cam followers 398 for movement relative to the supportmember 406 along the longitudinal axis of the cam follower 398.

In operation, the operator orients the saw blade 30 in either anup-cutting orientation (i.e., with the teeth 131 facing in a generallyupward direction) or a down-cutting orientation (i.e., with the teeth131 facing in a generally downward direction). After the operator hasoriented the saw blade 30 in a desired orientation with respect to thefront end 128 of the spindle 124, the operator selects a travel path forthe saw blade 30 by engaging the saw blade 30 with a workpiece, asdescribed above.

When an operator selects a first path, the operator moves an actuator(not shown), which moves the cam follower 398 into engagement with thefirst eccentric cam member 388. The operator can then activate themotor, which reciprocates the shaft 140 and the first eccentric cammember 388 about the axis of the shaft 140.

The engagement between the outer surface of the first eccentric cammember 388 and the cam follower 298 and between the cam follower 398 andthe rear portion 414 of the chassis 394 causes the tube chassis 394 topivot relative to the housing 22. This pivoting movement of the tubechassis 394 and the spindle 124, in combination with the reciprocatingmovement of the spindle 324 described above, causes the spindle 124 andthe saw blade 30 to move along the first orbital path.

When the operator selects the second path, the operator moves theactuator, which moves the cam follower 398 into engagement with thesecond eccentric cam member 390. The operator can then activate themotor, which reciprocates the shaft 140 and the second eccentric cammember 390 about the axis of the shaft 140.

The engagement between the outer surface of the second eccentric cammember 390 and the cam follower 298 and between the cam follower 398 andthe rear portion 414 of the chassis 394 causes the tube chassis 394 topivot relative to the housing 22. This pivoting movement of the tubechassis 394 and the spindle 324, in combination with the reciprocatingmovement of the spindle 324 described above, causes the spindle 324 andthe saw blade 30 to move along the second orbital path.

The foregoing description of the present invention has been presentedfor purposes of illustration and description. Furthermore, thedescription is not intended to limit the invention to the form disclosedherein. Consequently, variations and modifications commensurate with theabove teachings, and the skill or knowledge of the relevant art, arewithin the scope of the present invention. The embodiments describedherein are further intended to explain best modes known for practicingthe invention and to enable others skilled in the art to utilize theinvention in such, or other, embodiments and with various modificationsrequired by the particular applications or uses of the presentinvention. It is intended that the appended claims be construed toinclude alternative embodiments to the extent permitted by the priorart.

1. A reciprocating saw comprising: a housing; a spindle mounted forreciprocation relative to the housing, the spindle having an end adaptedto receive a saw blade, the saw blade having a first orientationrelative to the spindle to have a first cutting direction and a secondorientation relative to the spindle to have a second cutting directionopposite the first cutting direction; and a drive assembly connected tothe spindle and operable to selectively drive the saw blade along afirst path of travel during a first cutting stroke and along a secondpath of travel during a second cutting stroke, the first path of travelbeing characterized by movement at least partially in the first cuttingdirection and the second path of travel being characterized by movementat least partially in the second cutting direction.
 2. The reciprocatingsaw of claim 1, wherein the saw blade is movable along the first path oftravel during a first return stroke.
 3. The reciprocating saw of claim2, wherein the saw blade is movable along the second path of travelduring a second return stroke.
 4. The reciprocating saw of claim 3, andfurther comprising an adjustment assembly operable to change movement ofthe saw blade between the first path of travel and the second path oftravel.
 5. The reciprocating saw of claim 1, wherein the drive assemblyis an orbital drive assembly, and wherein the first path of travel is anorbital path.
 6. The reciprocating saw of claim 5, and furthercomprising a locking assembly having a locked position, in which thelocking assembly substantially prevents orbital movement of the sawblade, and an unlocked position, in which orbital movement of the sawblade along the orbital path is allowed.
 7. The reciprocating saw ofclaim 5, wherein the second path of travel is a second orbital path. 8.The reciprocating saw of claim 7, and further comprising an orbitaladjustment assembly operable to change movement of the saw blade betweenthe first-mentioned orbital path and the second orbital path.
 9. Thereciprocating saw of claim 1, wherein the drive assembly is operable toselectively drive the saw blade along a third path of travel during athird cutting stroke, the third path of travel being different than thefirst path of travel and the second path of travel.
 10. Thereciprocating saw of claim 9, wherein the third path of travel ischaracterized by movement at least partially in the first cuttingdirection.
 11. The reciprocating saw of claim 9, wherein the third pathof travel is characterized by movement at least partially in the secondcutting direction.
 12. The reciprocating saw of claim 9, wherein thethird path of travel is characterized by movement in a substantiallylinear direction.
 13. A method of reciprocating a spindle of areciprocating saw, the reciprocating saw including a housing, thespindle having an end adapted to support a saw blade for reciprocatingmovement relative to the housing, the method comprising the acts of:securing the saw blade to the end of the spindle in a first orientation,in which the saw blade has a first cutting direction; reciprocating theend of the spindle such that the saw blade moves along a first path oftravel relative to the housing, the first path of travel beingcharacterized by movement at least partially in the first cuttingdirection; adjusting the orientation of the saw blade relative to thespindle from the first orientation to a second orientation, in which thesaw blade has a second cutting direction opposite the first cuttingdirection; and reciprocating the end of the spindle such that the sawblade moves along a second path of travel relative to the housing, thesecond path of travel being characterized by movement at least partiallyin the second cutting direction.
 14. The method of claim 13, wherein thesaw blade is movable along the first path of travel during a firstcutting stroke and along the same first path of travel during a firstreturn stroke.
 15. The method of claim 14, wherein the saw blade movesalong the second path of travel during a second cutting stroke and alongthe same second path of travel during a second return stroke.
 16. Themethod of claim 15, wherein the reciprocating saw includes an adjustmentassembly, and wherein the act of adjusting the orientation of the sawblade relative to the spindle from the first orientation to the secondorientation includes the act of adjusting movement of the saw bladebetween the first path of travel and the second path of travel with theadjustment assembly.
 17. The method of claim 13, wherein thereciprocating saw includes an orbital drive assembly, and wherein theact of reciprocating the end of the spindle such that the saw blademoves along the first path of travel includes the act of moving the endof the saw blade along an orbital path.
 18. The method of claim 17,wherein the reciprocating saw includes a locking assembly, and whereinthe act of moving the end of the saw blade along the orbital pathincludes the act of moving the locking assembly from a locked position,in which the locking assembly substantially prevents orbital movement ofthe saw blade, toward an unlocked position, in which orbital movement ofthe saw blade is allowed.
 19. The method of claim 17, wherein the act ofreciprocating the end of the spindle such that the saw blade moves alongthe second path of travel relative to the housing includes the act ofmoving the end of the spindle along a second orbital path.
 20. Themethod of claim 19, wherein the reciprocating saw includes an orbitaladjustment assembly, and wherein the method further comprises the act ofchanging the movement of the saw blade between the first-mentionedorbital path and the second orbital path with the orbital adjustmentassembly.
 21. The method of claim 13, and further comprising the act ofreciprocating the end of the spindle such that the saw blade moves alonga third path of travel relative to the housing, the third path of travelbeing different than the first path of travel and the second path oftravel.
 22. The method of claim 21, wherein the third path of travel ischaracterized by movement at least partially in the first cuttingdirection.
 23. The method of claim 21, wherein the third path of travelis characterized by movement at least partially in the second cuttingdirection.
 24. The method of claim 21, wherein the third path of travelis characterized by movement in a substantially linear direction.
 25. Areciprocating saw comprising: a housing; a spindle mounted forreciprocation relative to the housing, the spindle having an end adaptedto receive a saw blade, the saw blade having a first orientationrelative to the spindle to have a first cutting direction and a secondorientation relative to the spindle to have a second cutting directionopposite the first cutting direction; and an orbital drive assemblyconnected to the spindle and operable to selectively drive the saw bladealong a first path of travel during a first cutting stroke and along asecond path of travel during a second cutting stroke, the first path oftravel being a first orbital path characterized by movement at leastpartially in the first cutting direction and the second path of travelbeing a second orbital path characterized by movement at least partiallyin the second cutting direction.
 26. The reciprocating saw of claim 25,and further comprising an adjustment assembly operable to changemovement of the saw blade between the first path of travel and thesecond path of travel.
 27. The reciprocating saw of claim 25, andfurther comprising a locking assembly having a locked position, in whichthe locking assembly prevents orbital movement of the saw blade, and anunlocked position, in which orbital movement of the saw blade isallowed.
 28. The reciprocating saw of claim 25, wherein the driveassembly is operable to selectively drive the saw blade along a thirdpath of travel during a third cutting stroke, the third path of travelbeing different than the first path of travel and the second path oftravel.
 29. The reciprocating saw of claim 28, wherein the third path oftravel is characterized by movement at least partially in the firstcutting direction.
 30. The reciprocating saw of claim 28, wherein thethird path of travel is characterized by movement at least partially inthe second cutting direction.
 31. The reciprocating saw of claim 28,wherein the third path of travel is characterized by movement in agenerally linear direction.